So why not show all events live, as they happen, on the Web? Responding to the question on a conference call with reporters, NBC research chief Alan Wurtzel said he doesn't really know "the underlying contractual reasons" the network is embargoing events online.

This doesn't sound convincing to us. Here's a more plausible argument: Going into the games, NBC had no idea what kind of audiences they would get for an Olympics held on the other side of the globe, in the era of YouTube. So it erred on the side of limiting Web footage, for fear of canabilizing its TV audience. As it turns out, the TV ratings have been startlingly high, and are on pace to exceed the Atlanta games 12 years ago.

Still, TV is the cash cow and by far the biggest source of audience. NBC says 90% of Olympic audiences are watching on TV only, versus 10% watching both TV and online. NBC's estimate of their total audience on TV, online, mobile and on VOD are in the document below. Note the online numbers jump on Monday, when presumably more people watched, or attempted to watch, while at work. These are not unduplicated numbers, so there's plenty of overlap, especially between TV and online.

Another factoid: Olympic TV ratings have been highest on the West Coast (San Diego is the strongest market) meaning audiences either don't know how Michael Phelps has done, or they do know and don't care -- they just want to watch him on TV. Since NBC doesn't get penalized, except on cranky blogs, expect tape delays -- and other restrictions on Olympic viewing -- to continue at least until the next Olympiad.